...Yuqi Wang; Bernd Riedstra; Ton Groothuis ABSTRACT Offspring phenotypes can be affected by maternal testosterone and androstenedione (A4), which are considered a tool of mothers to adjust offspring to a fluctuating environment. Yet testosterone and A4 are very rapidly metabolized by developing avian...

... to cleaning services alters indicators of health status such as body condition, immunity and the steroids cortisol and testosterone in four client damselfish species Pomacentrus amboinensis , Amblyglyphidodon curacao , Acanthochromis polyacanthus and Dischistodus perspicillatus . To do so, we took advantage...

...: the avian egg is thus ‘multivariate’. Multivariate effects on offspring phenotype were evaluated in a study on captive zebra finches, by simultaneously manipulating maternally derived antibodies (MAb) by lipopolysaccharide (LPS) treatment of mothers and injection of testosterone into the egg yolk. LPS...

... , L. B. , Fusani , L. , Hernandez , E. , Billo , T. J. , Sheldon , K. S. , Wise , P. M. and Schlinger , B. A. ( 2007 ). Testosterone and its effects on courtship in golden-collared manakins (Manacus vitellinus): seasonal, sex, and age differences . Horm. Behav.   51 , 69...

... in response to subsequent injections of exogenous kisspeptin. Saline-treated controls showed a robust increase in circulating testosterone in response to kisspeptin; however, this response was blocked in LPS-treated animals. Circulating luteinizing hormone (LH) levels were elevated in response to kisspeptin...

... we measured baseline testosterone, testosterone after an acute handling stressor, and capacity to produce testosterone after hormonal stimulation. In a 2×2 design, we then killed males from the two chronic treatment groups either immediately or after an acute stressor to investigate the effect...

.... A growing body of evidence indicates testosterone can regulate growth, thus the development of SSD, and sexual dichromatism. However, the mechanism(s) underlying these effects are conjectural, including possible conversions of testosterone to estradiol (E 2 ) or 5α-dihydrotestosterone (DHT). In the present...

... investigated the effect of total ovariectomy, prepubertal ovariectomy, unilateral ovariectomy, and total ovariectomy followed by exogenous estradiol, dihydrotestosterone or testosterone treatment, on female growth in comparison to males and reproductively active females. The present results and the results...

...Marco Parolini; Andrea Romano; Cristina Daniela Possenti; Manuela Caprioli; Diego Rubolini; Nicola Saino ABSTRACT Hormone-mediated maternal effects generate variation in offspring phenotype. In birds, maternal egg testosterone (T) exerts differential effects on offspring traits after hatching...

.... Surprisingly, males pursuing the fixed dwarf male tactic showed the highest free and conjugated 11-KT and testosterone (T) levels. Our experimental social challenges significantly affected the free 11-KT levels of bourgeois males, but the androgen responses did not differ between challenges involving different...

...Willow R. Lindsay; Douglas G. Barron; Michael S. Webster; Hubert Schwabl ABSTRACT In males it is frequently testosterone (T) that activates the expression of sexually selected morphological and behavioral displays, but the role of T in regulating similar traits in females is less clear. Here, we...

... of this axis to endocrine stimulation. Here, we present data from an experiment in Abert's towhees, Melozone aberti , using gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) challenges to investigate whether energy deficiency modulates the plasma testosterone responsiveness of the HPG axis...

... testosterone increased in response to photostimulation in ad libitum -fed but not in food-restricted birds. Food availability did not, however, affect the plasma testosterone increase resulting from a gonadotropin-releasing hormone-I (GnRH) or a luteinizing hormone (LH) challenge. The number of hypothalamic...

... development, we experimentally administered three different androgen doses of the naturally occurring mixture of yolk testosterone and androstenedione to spotless starling eggs ( Sturnus unicolor ). We found that yolk androgens induce a non-linear dose–response pattern in several traits. Androgens had...

... no competing financial interests. 8 7 2013 11 2 2014 © 2014. Published by The Company of Biologists Ltd 2014 Teleost Testosterone 11-ketotestosterone Cortisol Territorial aggression Interspecific behavior Animals live in competitive social environments in which each...

... of testosterone and free corticosterone and negatively correlated with corticosterone binding globulin capacity. These data are discussed in terms of the behavioral ecology of host and vector, and suggest that both seasonal increases in vector activity and relapse of latent (i.e. dormant) infections contribute...

... decreased it by ~4%. SD photoperiod had no effect on reproductive status and leptin levels, whereas LD males increased testes mass and serum testosterone, but the photoperiod had no effect on leptin levels. Vasopressin administration decreased LD-induced reproductive enhancement. Because no consistent...

... of a single pattern built around testosterone-mediated interplay between mate choice, parasitism and predation. [email protected] 25 3 2012 12 7 2012 © 2013. Published by The Company of Biologists Ltd 2013 anti-predator behavior behavioral manipulation major urinary proteins...

... in territorial defense vs sperm production, etc.) is compromised as the expression of morph-coding genes is only visualized in one sex. Here, we circumvented this problem by first characterizing oxidative stress traits in both sexes and then using testosterone implants in females to expose their otherwise...

...Mark L. Roberts; Katherine L. Buchanan; Matthew R. Evans; Raul H. Marin; Daniel G. Satterlee SUMMARY The immunocompetence handicap hypothesis (ICHH) suggests that the male sex hormone testosterone has a dual effect; it controls the development and expression of male sexually selected signals...